In "System Preferences > Notifications and Focus" there are two entries for KM, one labelled "Keyboard Maestro" and one labelled "Keyboard Maestro Engine"
Toggling "Keyboard Maestro Engine" on / off does exactly as I'd expect for notifications from KM (on/off).. but the other "Keyboard Maestro" has no apparent effect no matter the status of the "engine"... what does that do and what is the recommended setting On or Off?